---
schema_version: "secwatch.filing_event.v1"
accession: "0001171843-22-007974"
form_type: "8-K"
ticker: "APTOF"
cik: "0000882361"
company_name: "Aptose Biosciences Inc."
filed_at: "2022-12-12T23:59:59+00:00"
generated_at: "2026-06-21T06:33:42.295059+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Aptose reports tuspetinib CRs across 4 dose levels in r/r AML; establishes $50M ATM facility

## Summary
- Tuspetinib monotherapy yielded 38.1% response in FLT3+ and 19% in FLT3-WT r/r AML across 40-160mg doses.
- Luxeptinib G3 formulation shows up to 18-fold bioavailability improvement; continuous dosing initiated in AML patients.
- Aptose entered ATM equity distribution agreement with JonesTrading for up to $50M common share sales on Nasdaq.
- Tuspetinib selected 120mg as monotherapy expansion dose and 80mg for venetoclax combo in APTIVATE trial.

## SEC filing metadata
- accession: 0001171843-22-007974
- form_type: 8-K
- ticker: APTOF
- cik: 0000882361
- company_name: Aptose Biosciences Inc.
- filed_at: 2022-12-12T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 1.01, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/882361/000117184322007974/0001171843-22-007974-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/882361/000117184322007974/f8k_120922.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001171843-22-007974
- JSON: https://secwatch.observer/filing/0001171843-22-007974.json
- Plain text: https://secwatch.observer/filing/0001171843-22-007974.txt

## Key facts
- Material Agreements
  Aptose Biosciences Inc. entered into Equity Distribution Agreement with JonesTrading Institutional Services LLC (effective 2022-12-09).
  - Action: entry
  - Agreement: atm program
  - Counterparty: JonesTrading Institutional Services LLC
  - Effective: 2022-12-09
  source text: On December 9, 2022, Aptose Biosciences Inc. entered into an Equity Distribution Agreement (the “EDA”) with JonesTrading Institutional Services LLC, as agent, (the “Agent”) in connection with the establishment of an “at-the-market” sales facility.
  evidence_url: https://www.sec.gov/Archives/edgar/data/882361/000117184322007974/0001171843-22-007974-index.htm

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.